no... :notsure: ... huh???
if you are cycling, and you do a water change, it decreases your ammonia, not your bacteria. Too much ammonia will kill the bacteria that converts the nitrites to nitrates... therefore lenghtening your cycle. Also, if you have 1/2 of the amount of ammonia, it accomplishes the same as having the full amount because it gets that bacteria to grow. Were you saying that doing a water change removes the bacteria you've produced, and that'll cause a spike when adding livestock? i couldn't quite follow what you said... if that's what you were saying, doing a water change doesn't decrease your bacteria because it grows on your rock and hard surfaces. While some of it may be floating in the water, the majority is colonized on your rock, walls, and sandbed.